The present invention relates to surgical procedures, and in particular to a probe incorporating a dilator and a method for its use in connection with minimally invasive surgery.
Minimally invasive surgery techniques have been used in the past for spinal disc replacement procedures.
There are known devices for dilatation of soft tissue structures of the human body, including blood vessels, other ducts, bowels, and other lumens. Certain dilators are known to incorporate inflatable members utilized to separate soft tissue, including muscular tissue, in order to provide visibility and access to portions of the anatomy that are of interest.
In some surgical procedures it is important to determine where certain structures are located in order not to damage them. For example, it is desired not to sever nerves or some blood vessels or other ducts or conduits for fluid. While fluoroscopy can be used to guide surgeons in the placement of probes used to guide certain types of dilators, other techniques are often desirable for determining exactly where a surgical instrument should be placed in order to avoid damaging structures such as nerves.
In preparing for spinal disc replacement or spinal fusion using minimally invasive surgical procedures, a probe may be equipped with an electrode on its tip, with a suitable electrical conductor being connected to the electrode and extending along the probe to a proximal part. An electrical signal can be supplied through the electrode and a resulting response can be interpreted to identify nerves, vascular, and muscular structures in the vicinity of the electrode on the distal tip of the probe.
Presently utilized procedures in connection with a lateral approach to a lumbar spinal disc require creation of a pathway through the psoas major muscle to obtain access to a diseased intervertebral disc. Dilatation of an opening made through the psoas muscle is required to provide access to a patient's spinal column and has been performed in the past by placing successively larger tubular dilators over and along a probe, until a suitably large dilator has been moved into place. This, however, requires an appreciable amount of time and results in undesirable amount of trauma to the tissue between the incision where the probe has been inserted and the required dilated opening through the psoas muscle and other tissues surrounding the spinal column.
What is desired, then, is an improved way to form and dilate an opening through soft tissue, precisely in a required location, in order to provide necessary workspace in which to perform a surgical procedure, yet avoid damage to critical tissue such as nerves surrounding an opening through which a minimally invasive surgical procedure is to be performed.